Friday Rockpile links, 3/7: Jon Gray, Jordan Lyles, a challenge flag and more

Do you like stories about prospects? Of course you do. Prospects are that dragon that baseball fans are always chasing, especially fans of losing teams. "We suck now, but when that kid who blow-torched AA gets here ... everything is gonna change." So here's your fix: Troy Renck profiles Jon Gray, he of the 100 mph fastball and devastating slider. Come for the prospect goodness, stay for the outdated cultural references. Love ya Renck.

Various other notes from Renck. They include injury updates, quotes from pitchers vying for fifth starter, and Larry Walker arriving in camp as a guest instructor.

Jordan Lyles strong, but Rockies sloppy on defense in loss. This is becoming a common refrain, even if it's mostly non-regulars making the miscues.

Walt Weiss got to throw the challenge flag yesterday for the first time. The call was upheld, but it was interesting to see replay in action. The delay was minimal.

Ben Lindbergh of Grantland looks into the recent trend of increased job security for MLB general managers. It's a good read, as it details the rise of post-Moneyball front offices. The long-tenured Dan O'Dowd is bringing up the average of GM lifespans.

Jeff Sullivan of Fangraphs looks into the projected strength of the divisions. The NL West is going to be a tough nut to crack this year.